1. Field of the Invention
The present invention relates to a pipe joint arrangement for a drainage pipe or the like, and further, it relates to a pipe joint structure connecting the pipe and the pipe joint of the drainage pipe or the like.
2. Description of the Prior Art
Conventionally, in drain pipes, connections between a vertical drain pipe and a horizontal branch drain pipe, as well as a vertical drain pipe and a horizontal main drain pipe, or between vertical drain pipes or horizontal branch drain pipes themselves, are performed via drain pipe joints, such connecting structures being connected, as in the drain pipe joint structure K2 shown in FIG. 1, by inserting a drain pipe 1 in a housing portion 23 having a flange portion 24 formed in a drain pipe joint 22, engaging a flexible packing 26 installed in the drain pipe 1 with a taper portion 25 formed in the inner periphery of the flange portion 24, and securing, by means of the flange portion 24 of the drain pipe joint 22 and three bolts, a locking flange 28 installed in the drain pipe 1 via a lock ring 27.
Also, in the case of drain pipe joint structure K3 shown in FIG. 4, an external thread 33 is formed in the outer periphery of a drain pipe joint 32, and the drain pipe 1 is inserted in the inner periphery of the drain pipe joint 32 by abutting it against a stop face 34 formed in the drain pipe joint 32. Also, a nut member 36 formed in the inner periphery by an internal thread 37 is arranged on the outer periphery of the drain pipe 1 via an O ring 35, and a band 39 is connected to the nut member 36 via a lug 38. Then, the lug 38 of the nut member 36 is rotated and the band tightened to thereby fix the drain pipe 1 and the drain pipe joint 22 together.
In the case of the drain pipe joint structure K4 shown in FIG. 5, a "slip on" type packing 44, mounted in the joint portion of a drain pipe joint of a heading collar pipe used in slab type collective housing (apartment buildings etc.) in particular for waste water, miscellaneous waste, etc. for example, is inserted in a pressure welded state within a joint portion 43 of a waste water pipe joint 42. Then, the drain pipe 1 is pressure weld-inserted into the slip on type packing 44 and the drain pipe 1 and drain pipe joint 42 are connected.
Further, in the case of another drain pipe joint structure, a flexible packing is mounted in a drain pipe at the end portion of which a collar for preventing a drain pipe from falling off is formed, and this is inserted into a drain pipe joint. The joint portion of the drain pipe joint has a housing portion formed therein and in the housing portion an internal thread portion and a taper portion to which the packing is engaged on the far side from the internal thread portion. A bushing on whose outer circumference a thread is formed engages with the internal thread portion formed in the housing portion of the drain pipe joint, compressing the packing. Also, a number of stopper nuts for locking the drain pipe into the bushing are arranged perpendicularly to the axial direction of the bushing.
However, in recent years in buildings for collective housing (apartments) etc., individual units are being utilized to the maximum limits of their areas. Along with this, not only has the horizontal space allowable for piping for drain pipes and the like installed to circulate residential waste water been reduced in size and the layout of piping for drainage inevitably reduced in size, but also, along with the advancing age of the population, low floor designs for preventing elderly people from stumbling are becoming common and slab heading collar piping in which the horizontal branch drain pipes are arranged extremely close on the concrete slab have become inevitable. Therefore, it has become necessary to consider many matters in pipe construction for drain piping.
For example, as shown in FIG. 2, where carrying out connected work on a drain pipe being installed between a corner of a wall C and another drain pipe, the work area is extremely narrow and when securing bolts and nuts, cases where the wall C and drain pipe interfere with the tools and they cannot be used and the work must take an extremely long time are common.
For instance, in the case of the drain pipe joint structure K2 shown in FIG. 1, since the flange portion 24 of the drain pipe joint 22 and the locking flange 28 are secured by bolts in three places, the positions of the bolts are determined at the time when the drain pipe joint 22 is installed. Since the positions of the bolts are normally separated by a third of the circumference of the flanges, any one of the bolts is located close to the wall or the other drain pipe. Consequently, the bolt cannot be tightened using a tool. Also, if the bolt is forcibly tightened, the joint is only partially secured, leaks occur between the packing 26 and the drain pipe 1 or flange portion 24, and each section is damaged. For this reason, if the piping is to be installed correctly without partial securing, it takes a very long time and work time is lost.
Also, in the case of the drain pipe joint structure K3 shown in FIG. 4, since the drain pipe 1 is connected to the drain pipe joint 32 by rotating the lug 38 of the nut member 36 installed on the outer periphery of the drain pipe 1, depending on the tightened condition of the nut member 36, when the lug 38 is positioned near a wall or on a concrete slab tools are interfered with and cannot be used.
In addition, as a horizontal drain pipe joint connecting a toilet drain pipe of a wall drainage P-type toilet used in particular in collective housing, in the case of a drain pipe joint structure K4 of a type wherein a "slip on" type packing 44 is installed in a joint portion 43 of a drain pipe joint 42 as shown in FIG. 5, the drain pipe joint 42 is normally arranged so that it is housed at the vertical drain pipe side of a curtain wall S disposed between the toilet and the vertical drain pipe. Also, the interior design work on the washroom is normally performed prior to installation of the toilet drain pipe and the toilet itself, the toilet drain pipe 1 passes through the curtain wall S and opens as a hole in alignment with the joint portion 43 of the drain pipe joint 42, and in this state interior decoration is carried out. Then, the toilet is installed after the toilet drain pipe 1 and the drain pipe joint 42 are connected and a sealing plate is attached to the hole portion Sa in the curtain wall and faced.
Therefore, when the toilet drain pipe 1 is connected to the drain pipe joint 42, the toilet drain pipe 1 must be inserted in a state where the joint portion 43 of the drain pipe joint 42 is difficult to inspect. Further, where the toilet drain pipe cannot reach its predetermined position and the contact area of the packing 44 is insufficient, leakage of contaminated air inside the drain water and drain pipe easily occurs and, in addition, as shown in FIG. 6, where the toilet drain pipe 1 is inserted at an angle, the packing 44 peels off from the joint portion of the drain pipe joint and there is the possibility of water leakage or odor leakage due to complex deformation being incurred, thus various types of methods are being examined in order to prevent this.
Also, in a drain pipe joint structure of a type in which a pipe loosening prevention collar is formed at the end of the drain pipe and a bushing provided with a stopper screw is used, because squeaking noises occur between the drain pipe and the stopper screw due to expansion and compression of the drain pipe, currently application of these types of structures is falling off.